<template>
  <view>
    <!-- 方式一，通过冒泡监听事件 -->
    <!-- <my-search @click.native="gotoSearch"></my-search> -->
    <!-- 方式二，通过父子通信 -->
    <my-search @click="gotoSearch"></my-search>
    <view class="scroll-view-container">
      <scroll-view scroll-y="true" class="left-scroll-view" :style="{ height: windowHeight + 'px' }">
        <block v-for="(item, index) in cateList" :key="index">
          <view class="left-scroll-view-item" :class="{ active: index === active ? 'active' : '' }" @click="activeChanged(index)">{{ item.cat_name }}</view>
        </block>
      </scroll-view>
      <scroll-view scroll-y="true" class="right-scroll-view" :style="{ height: windowHeight + 'px' }" :scroll-top="scrollTop">
        <view class="cate-lv2" v-for="(item2, index2) in catelevel2" :key="index2">
          <view class="cate-lv2-title">/ {{ item2.cat_name }} /</view>
          <view class="cate-lv3-list">
            <view class="cate-lv3-item" v-for="(item3, index3) in item2.children" :key="index3" @click="gotoGoodsList(item3)">
              <image :src="item3.cat_icon"></image>
              <text>{{ item3.cat_name }}</text>
            </view>
          </view>
        </view>
      </scroll-view>
    </view>
  </view>
</template>

<script>
import tabbarBadge from '@/mixins/tabbar-badge.js';
export default {
  name: 'CatePage',
  mixins: [tabbarBadge],
  components: {},
  data() {
    return {
      windowHeight: 0, // 屏幕可视高度
      cateList: [], // 一级分类
      active: 0, // 激活的分类的索引
      catelevel2: [], // 二级分类
      scrollTop: 0 // 右侧滚动距离
    };
  },
  created() {},
  mounted() {},
  onLoad() {
    // 获取屏幕的可视高度
    let info = uni.getSystemInfoSync();
    this.windowHeight = info.windowHeight - 50;
    this.getCateList();
  },
  methods: {
    gotoSearch() {
      uni.navigateTo({
        url: '/subpkg/search/search'
      });
    },
    gotoGoodsList(item) {
      uni.navigateTo({
        url: '/subpkg/goods_list/goods_list?cid=' + item.cat_id
      });
    },
    activeChanged(index) {
      this.active = index;
      this.catelevel2 = this.cateList[index].children;
      this.scrollTop = this.scrollTop === 0 ? 1 : 0;
    },
    async getCateList() {
      let {
        data: {
          message,
          meta: { status }
        }
      } = await uni.$http.get('/api/public/v1/categories');
      if (status !== 200) {
        return uni.$showMsg();
      }
      this.cateList = message;
      this.catelevel2 = this.cateList[0].children;
    }
  }
};
</script>

<style lang="scss">
.scroll-view-container {
  display: flex;
}
.left-scroll-view,
.right-scroll-view {
  height: 300px;
}
.left-scroll-view {
  width: 120px;
}
.left-scroll-view-item {
  line-height: 60px;
  background-color: #f7f7f7;
  text-align: center;
  font-size: 12px;
  &.active {
    background-color: #ffffff;
    position: relative;
    // 渲染激活项左侧的红色指示边线
    &::before {
      content: ' ';
      display: block;
      width: 3px;
      height: 30px;
      background-color: #c00000;
      position: absolute;
      left: 0;
      top: 50%;
      transform: translateY(-50%);
    }
  }
}
.cate-lv2-title {
  font-size: 12px;
  font-weight: bold;
  text-align: center;
  padding: 15px 0;
}
.cate-lv3-list {
  display: flex;
  flex-wrap: wrap;
  .cate-lv3-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    width: 33.33%;
    margin-bottom: 10px;
    image {
      width: 60px;
      height: 60px;
    }
    text {
      font-size: 12px;
    }
  }
}
</style>
